 |
|
|
 |
Dr. Sterling replies To the Editor: Once again we hear from Ferrari and Russell, who cite only their opinion-based papers, thereby negating any attempt to engage them in valid scientific debate in a prestigious peer-reviewed journal such as this. They believe that, "[T]he most single important factor determining whether or not chronic WAD develops after an MVA is where one lives." At odds with this belief is a recent systematic review on prognosis following whiplash injury that failed to identify culture as a predictor of poor outcome1. The Greek study2 quoted by Ferrari and Russell was included in this review, but was not rated as a particularly high quality study. The German study to which they refer comprised 43 subjects with acute whiplash injury, of whom only 32 (74%) participants attended for followup assessment3 — which can hardly be considered as a population based study! While a full and clear picture of these "whiplash" conditions is yet to be elucidated, one fact is quite apparent. They are remarkably complex, with diverse clinical manifestations that can include motor dysfunction, psychological distress, and, in some patients, evidence of sensory dysfunction. The phenomenon of sensory hypersensitivity to a series of stimuli, both noxious and non-noxious, has been unequivocally demonstrated in numerous cohorts, in the acute and chronic contexts, by researchers from many disciplines involved in pain medicine (including physiotherapists)4-10. Two studies, one conducted in Denmark and the other in Australia, have shown that sensory hypersensitivity, often in association with other prognostic indicators such as pain intensity and some psychosocial factors, is predictive of poor recovery6,11. While it is thought that the sensory hypersensitivity is a reflection of altered nociception, interpretation of many of the quantitative sensory tests used in clinical research is necessarily dependent upon the patients' cognitive responses. However, evidence of spinal cord hyperexcitability as measured by reflex muscle responses following direct electrical stimulation to a peripheral nerve has been demonstrated in both chronic whiplash and other painful musculoskeletal conditions12,13. This reflex response is robust in the presence of anxiety and catastrophization and provides what can be considered as "objective" evidence of central hyperexcitability14-16. As a side issue, it is disappointing that Ferrari and Russell have chosen to launch an ad hominem attack upon the physiotherapy profession from their self-appointed position as "trained physicians" who are apparently custodians of the truth in these matters. They would be better advised to heed the words of William J. Mayo, who wisely said: "Scientific truth which I formerly thought of as fixed, as though it could be weighed and measured, is changeable. Add a fact, change the outlook, and you have a new truth. Truth is a constant variable. We seek it, we find it, our viewpoint changes, and the truth changes with it"17. MICHELE STERLING, PhD, MPhty, Bphty, Senior Lecturer, Division of Physiotherapy, School of Health and Rehabilitation Sciences, The University of Queensland, St. Lucia, Australia 4072. REFERENCES 1. Scholten-Peeters G, Verhagen A, Bekkering G, et al. Prognostic factors of whiplash associated disorders: a systematic review of prospective cohort studies. Pain 2003;104:303-22. [MEDLINE] 2. Partheni M, Constantoyannis C, Ferrari R, et al. A prospective study of the outcome of acute whiplash injury in Greece. Clin Exp Rheumatol 2000;18:67-70. [MEDLINE] 3. Richter M, Ferrari R, Otte D, et al. Correlation of findings, collision parameters and psychological factors in the outcome of whiplash associated disorders. J Neurol Neurosurg Psychiatry 2004;75:758-64. [MEDLINE] 4. Sheather-Reid R, Cohen M. Psychophysical evidence for a neuropathic component of chronic neck pain. Pain 1998;75:341-7. [MEDLINE] 5. Moog M, Quintner J, Hall T, Zusman M. The late whiplash syndrome: a psychophysical study. Eur J Pain 2002;6:283-94. [MEDLINE] 6. Kasch H, Qerama E, Bach F, Jensen T. Reduced cold pressor pain tolerance in non-recovered whiplash patients: a 1 year prospective study. Eur J Pain 2004;9:561-9. [MEDLINE] 7. Koelbaek-Johansen M, Graven-Nielsen T, Schou-Olesen A, Arendt-Nielsen L. Muscular hyperalgesia and referred pain in chronic whiplash syndrome. Pain 1999;83:229-34. [MEDLINE] 8. Sterling M, Jull G, Vicenzino B, Kenardy J. Sensory hypersensitivity occurs soon after whiplash injury and is associated with poor recovery. Pain 2003;104:509-17. [MEDLINE] 9. Scott D, Jull G, Sterling M. Sensory hypersensitivity is a feature of chronic whiplash associated disorders but not chronic idiopathic neck pain. Clin J Pain 2005;21:175-81. [MEDLINE] 10. Curatolo M, Petersen-Felix S, Arendt-Nielsen L, et al. Central hypersensitivity in chronic pain after whiplash injury. Clin J Pain 2001;17:306-15. [MEDLINE] 11. Sterling M, Jull G, Kenardy J. Physical and psychological predictors of outcome following whiplash injury maintain predictive capacity at long term follow-up. Pain 2006;122:102-8. [MEDLINE] 12. Sandrini G, Arrigo A, Bono G, Nappi G. The nociceptive flexion reflex as a tool for exploring pain control systems in headache and other pain syndromes. Cephalalgia 1993;13:21-7. [MEDLINE] 13. Banic B, Petersen-Felix S, Andersen O, et al. Evidence for spinal cord hypersensitivity in chronic pain after whiplash injury and in fibromyalgia. Pain 2004;107:7-15. [MEDLINE] 14. Sterling M, Kenardy J, Souvlis T, et al. Sensory hypersensitivity and psychological distress following whiplash injury: Is there a relationship? Pain across the lifespan [abstract]. Australian Pain Society 26th annual conference. Melbourne: APS; 2006. 15. French D, France C, France J, Arnott L. The influence of acute anxiety on assessment of nociceptive flexion reflex thresholds in healthy young adults. Pain 2005;114:358-63. [MEDLINE] 16. France C, France J, Absi M, et al. Catastrophizing is related to pain ratings, but not nociceptive flexion reflex threshold. Pain 2002;99:459-63. [MEDLINE] 17. Mayo W. Seventieth birthday anniversary of William J. Mayo. Annals of Surgery 1931;94:799-800.
|